Belarusian leader threatened to tap oil from Russia's transit pipeline amid tense negotiations with Moscow over tariffs.
Meanwhile, Vilnius is helping Minsk retain sovereignty by providing energy import alternatives, Lithuanian President Gitanas Nausėda said.
President Alexander Lukashenko said Belarus would start taking oil from a transit pipeline if Russia does not supply its neighbour with the required volumes of crude, the state news agency BelTA reported on Friday, according to Radio Free Europe.
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Russian oil flows to Belarus have dwindled since the beginning of the year, as Minsk and Moscow failed to agree terms for oil supplies for 2020.
"If Russia doesn't supply oil in necessary volumes, we would start taking it from the transit pipeline," the Belarusian leader said, referring to the Druzhba pipeline that crosses Belarusian territory and supplies about 1 million barrels of Russian oil to Europe.
The dispute over Russian oil supplies is part of wider political discord between Minsk and Moscow over forming a union.
Lithuanian intelligence said in a report earlier this month that "Russia's negotiations with Belarus on energy cooperation and deeper integration shift to political pressure".
"Russia seeks to increase its influence on Belarus by using its weak, non-diversified and dependent on Russian energy resources economy as the main lever," it said.
Robert Gilchrist, Washington's new ambassador to Lithuania, told BNS this week that the US expects to supply Belarus with natural gas via Lithuania's Klaipėda LNG terminal in the future.
On a visit to southeastern Belarus on February 14, Lukashenka told officials of his talks with Russian President Vladimir Putin in the Black Sea resort of Sochi last week, according to Radio Free Europe.
The Russian side hinted "at the incorporation of Belarus in return for unified energy prices," Lukashenko said, adding that he is "convinced that neither Russians nor Belarusians will ever want to follow this path".
Lithuanian president: gas supply alternatives help Belarus in talks with Russia
Lithuania is helping Minsk negotiate with Moscow on an equal footing by offering Belarus an alternative route for natural gas imports, said President Gitanas Nausėda.
"Our willingness for dialogue, which we have actually started, and our willingness to help Belarus retain sovereignty by providing it with energy alternatives allows Lukashenko to speak with Putin as an equal partner," Nausėda told Delfi TV on Thursday, according to BNS.
Read more: Belarus calls for regular oil imports via Baltics as first shipment arrives in Lithuania
"[Lukashenko] couldn't demand anything if he had no alternatives," the Lithuanian president.
"In a sense, we are creating the conditions for these negotiations between [...] two unequal parties to [have] negotiations on an equal footing," he added.
According to Nausėda, Belarus' competitiveness is now "guaranteed by artificially low energy prices".
"It goes without saying that Russia [...] is using this as a tool for blackmail," he said.
Read more: Lithuania nudges Belarus out of Russia's energy grip